Julia Schaefer’s fight name is Bruiser. “Because I bruise easily,” she qualifies. “Not because I cause bruises.”

But that’s probably not true.

In early July, before a crowd of hundreds at Norths Leagues Club in Sydney, a cheerful chant of “Bruiser! Bruiser! Bruiser!” rises as she enters the room. A camera trails Schaefer as she half-bounces, half-swaggers down an aisle, stopping to wave at her school-mum friends and blow a kiss to her husband. She is patted down (“presumably for knives – I don’t know”), her face smeared with Vaseline, and then the 40-year-old marketing consultant and mother of six-year-old twins walks up the stairs and into her first cage fight.

“I was like: ‘Right. This is it,’” she says. “The whole first round I just felt like I was in a parallel universe almost. It’s not me – to fight. That’s so unlike who I am. But I was loving it so much. Whether she hit me or not, I have no idea. I couldn’t feel it.”

Her opponent did hit her. Again, and over again. Schaefer had the better of her in the first round, got her opponent on her back – and while the woman then duly kicked Schaefer in the stomach until she was able to right herself, Schaefer felt nothing. Watching the video of the fight, Schaefer’s heart is palpitating. But on the night, she says, she was fine.

Schaefer has limited interest in mixed martial arts, or MMA. Even now, she doesn’t like to watch UFC professional fights – there’s too much blood. Her fight was the culmination of a 20-week program of waking at 4.30am, travelling to an inner Sydney gym, training for an hour and a half, then returning home in time for the morning alarm to make breakfast for her children.

She was a participant in Wimp2Warrior, an Australian MMA fitness program trying to bring the sport to new, lucrative audiences around the world. For about $2,500 a course, Wimp2Warrior promises “The Ultimate Human Transformation” which ends with participants fighting each other in the cage.

The tagline used to be “The Ultimate Human Experiment” but the founders say the hypothesis has been proved: anyone can be a cage fighter.

The course was founded by MMA coach Richie Cranny and ex-private wealth and stockbroking firm manager Nick Langton. This year, the company is on track to have 3,000 participants go through its program at more than 50 gyms, which have licensed it in eight countries – and it is growing exponentially. In the past three financial years, says Langton, revenue has increased by 100% year-on-year. The business currently turns over more than $6m annually. Langton says that if Wimp2Warrior meets its target of 1,000 gyms within five years it will be looking at revenues in the hundreds of millions of dollars.

Mixed martial arts, by its own estimation, is the fastest growing sport in the world. Over the past two decades its image has evolved from one of “human cockfighting” to a multibillion dollar professional sport, with global superstar coaches and fighters and a concerted push for inclusion in the Olympic Games.

When Cranny emigrated to Australia in 2003 from the UK, he spent years trying to establish amateur or recreational MMA programs in existing gyms, with no success. Eventually he opened his own gym and, in an effort to bring in new clientele to the sport, offered to train a civilian for six months for free, under the condition they would have an MMA fight at the end. Four hundred people applied. He took 25, and documented their progress online.

After a few seasons in his own gym, he licensed the program to gyms in Melbourne, London and Brisbane. It started spreading more rapidly after Irish supercoach John Kavanagh brought the program into his gym and became a partner.

“The vision behind it was to try to get regular people into the sport – people you wouldn’t expect,” says Cranny. “MMA naturally attracts a cohort of guys in their 20s that think it’s cool, but I’ve been in this sport for a long time and I can see what it can do for everyday people. The frustration was, it was almost impossible to get these people through the door.”

Wimp2Warrior presents itself as a “family”, a friendly consumer face for entry into MMA. In Australia the average age for male participants is 30 and female 31. The team say they have had people in their 60s complete the course, and they are focused on increasing female participation.

For Julia Schaefer, the ultimate goal of the course – fighting in a cage – was daunting not only for her, but for her ultra-pacifist husband who relocates spiders rather than kill them. Learning to throw punches, to hit other people, aiming for their face, and being hit in the face was confronting, especially for the women in her group.

“We got to the fight camp part of the training … and the coaches are constantly yelling – mostly at the girls – ‘Throw in your punches, throw in your punches! And we’re like ‘Really? Do we?’”

For participants, say the founders, there is a fitness appeal, but the magnitude of the final challenge is the critical component. “To be able to step into a cage and fight without fear, and be excited to do it, that’s very empowering,” says Cranny. “The whole point of the program is to keep people out of their comfort zone.”

The promise of transformation

At 5.30am on a cold Thursday morning, it’s still pitch black outside the SBG gym in Leichhardt. Coach Ben Power, with a brace supporting his entire left leg, has the demeanour of a neighbourhood cop. By 5.35, eight participants are doing short sprints and shoulder rolls up and down the mat floor, then are paired up to practice jujitsu floor grappling.

The room is full of gasps of exertion and little other sound, except the faint wafting of chill-out music emanating from the reception desk. After each grapple, the pairs slap each other a loose high-five or perfunctory fist bump.

By 6.15, patches of sweat smear the mat. Power walks between the grappling pairs, advising them on how to escape choke holds. It’s only week eight of the 20-week program, so there is no hitting. The first half of the program is grappling and conditioning. The second half is when participants practise striking. Observing one pair silently rolling on the floor, one trying to escape, the other trying to dominate, Power calmly reminds them: “This stuff works, but it’s much harder when the person on top is hitting you in the face.”

At 7am, the training is done. The sun is up, and the dew on the windows is slowly disappearing. Some participants hang around. Among them are a software engineer, physiotherapist, receptionist, someone who works in plumbing retail and a TV commercial director. They’re predominantly in their 20s and 30s, there is one woman, and most have had no experience in martial arts . They all have been drawn to the program, expensive and gruelling as it is, by the promise of transformation.

At the end of the Wimp2Warrior training session, everyone puts their hands together in a team building exercise. Photograph: Jessica Hromas/The Guardian

About three months out from their ultimate fight, the idea of the ultimate clash remains daunting. The TV director is “terrified”. There is half an octagon-shaped cage to the side of the training gym. They’ve been practising pushing each other up against it, and even that was a shock. “I thought it was going to be squishy,” says the software engineer, who gave up smoking 40 cigarettes a day four days before starting the course. “No. It’s very uncomfortable.”

‘It’s a risk, but life’s a risk’

There are concerns around MMA and other full-contact combat sports. There have been deaths in professional and amateur MMA due to concussion or weight cutting. The Australian Medical Association has, at state levels, advocated for banning mixed martial arts. Its position statement on combat sports, including boxing, recommends harm minimisation measures “until such time as combat sports are banned”.

Injury epidemiologist Dr Reidar Lystad of Macquarie University has conducted studies into combat sport injuries. “There’s no doubt about it: the risk is a lot higher than a lot of other sports, but not necessarily all other sports,” says Lystad.

“MMA athletes can expect to be injured once every four or five minutes of competition,” says Lystad. “The injury risk is very significant in other contact sports as well. American football, rugby, ice hockey have all had really serious issues with head injuries and concussions.

“If you’re an MMA fighter that fights only two or three times a year, compared to a rugby player that plays 20-plus matches in a season, I think the head injury exposure risk would be even greater in rugby than in MMA.”

Leichhardt coach Power concedes that if you were to watch the early days of MMA now, “it looks pretty crass”. But the sport has cleaned up, he argues, with the International Mixed Martial Arts Federation’s push for Olympic inclusion.

“It’s a risk, but life’s a risk,” he says. “All the doctors that [criticise MMA] will happily go down and watch the Melbourne Cup. They’ll sit in the bird cage with all their rich friends while a jockey gets thrown off and crushed by a horse. Come on. Don’t be hypocritical.”

Still, he says, concussion is an issue. “We do everything we can to try to mitigate it.” He says that participants are drilled on technique, and sparring is conducted under observation and primarily at low intensity. Cranny says the organisation has strict protocols on sparring and has not had a concussion in a finale fight. He says that while the Wimp2Warrior fights are conducted under IMMAF rules, referees are briefed that “this is a bucket-list thing” and so fights are stopped earlier than they would be at normal amateur level.

The Wimp2Warrior founders say the course actively discourages weight cutting – the practice of rapid weight loss before the fight in order to make a weight category – and that participants are weighed weekly to ensure they are on track for their fight weight. However, Schaefer believes some of those fighting in her cohort may have engaged in a level of water cutting.

Nothing feels hard any more

Watching her fight back on her phone, Julia Schaefer sips on a macadamia flat white. She began the series wanting to do something for herself and found it so “addictive” she is heading back to do the course again. During the series she lost 14% of her body weight, gained a six-pack and quit her job to set up her own consultancy. A few of those in her group quit their jobs during the course.

“The program strips you down to nothing. To your bare nothing. And you can rebuild the layers to be really strong,” she says.

The physical confrontation has something to do with it, she says. “You go, ‘OK. I’ve had a black eye, and I’m OK.” Nothing feels hard any more.

Schaefer says she wasn’t the only one in her cohort of 30 to 40 who underwent significant life change. “I’ve seen the transformation of some of the people. I’ve seen people come out of clinical depression, losing more than 20 kg, and just loving the endorphins and adrenaline. It’s an actual drug. We’re all just exhausted, and happy, and in control of our lives. It’s like we just know what we want now. Nothing can stop us. We’re warriors!”